High On/Off Ratio Carbon Quantum Dot-Chitosan Biomemristors with Coplanar Nanogap Electrodes

Abstract

A carbon-based natural nanocomposite material comprising carbon quantum dots (CQDs) is dispersed in a chitosan matrix. The CQD-chitosan nanocomposite serves as a solid polymer electrolyte layer of a biomemristor with a Au/CQD- chitosan/Al structure. The active layer of the CQD-chitosan nanocomposite is deposited from its solution on top of coplanar asymmetric nanogap (∼15 nm) Al-Au electrodes, patterned via adhesion lithography. The CQD-chitosan biomemristor presents a high on/off ratio (>106) and reproducible and reliable bipolar resistive switching behavior. An endurance of 160 cycles was recorded, while the high and low resistance states remained stable for more than 104 s. This study highlights the potential of both the CQD-chitosan material and nanogap electrode structures for application in nanoscale biocompatible memory devices.